Effect of deposition rate on properties of YBa2Cu3O7minus;dgr;superconducting thin films

摘要

Superconducting thin films of YBa2Cu3O7minus;dgr;on (100)thinsp;SrTiO3are preparedinsituby a pulsed laser deposition technique at deposition rates from 1 to 145 Aring;/s. Crystallinity of the films is examined by Rutherford backscattering in the channeling mode using a 2.2 MeV He+ion beam. The backscattering minimum yield (khgr;min) increases with the deposition rate. A khgr;minof 3percnt; is observed in the films deposited at the lowest deposition rate. Even at a deposition rate of 145 Aring;/s, the films show good crystallinity with khgr;minof 15percnt;, indicating epitaxial growth. The xhyphen;ray diffraction measurements show that the films have strongchyphen;axis orientation normal to the substrates. The films have metallic resistance versus temperature behavior with zero resistance temperatures of 90 K. The results indicate that the pulsed laser deposition technique could be used to deposit largehyphen;area films efficiently with adequate substrate movement.